3 * WordPress implementation for PHP functions either missing from older PHP versions or not included by default.
9 // If gettext isn't available
10 if ( !function_exists('_') ) {
17 * Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use.
23 * @param bool $set - Used for testing only
24 * null : default - get PCRE/u capability
25 * false : Used for testing - return false for future calls to this function
26 * 'reset': Used for testing - restore default behavior of this function
28 function _wp_can_use_pcre_u( $set = null ) {
29 static $utf8_pcre = 'reset';
31 if ( null !== $set ) {
35 if ( 'reset' === $utf8_pcre ) {
36 $utf8_pcre = @preg_match( '/^./u', 'a' );
42 if ( ! function_exists( 'mb_substr' ) ) :
43 function mb_substr( $str, $start, $length = null, $encoding = null ) {
44 return _mb_substr( $str, $start, $length, $encoding );
49 * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.
50 * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
51 * The behavior of this function for invalid inputs is undefined.
53 function _mb_substr( $str, $start, $length = null, $encoding = null ) {
54 if ( null === $encoding ) {
55 $encoding = get_option( 'blog_charset' );
58 // The solution below works only for UTF-8,
59 // so in case of a different charset just use built-in substr()
60 if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
61 return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
64 if ( _wp_can_use_pcre_u() ) {
65 // Use the regex unicode support to separate the UTF-8 characters into an array
66 preg_match_all( '/./us', $str, $match );
67 $chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
68 return implode( '', $chars );
72 [\x00-\x7F] # single-byte sequences 0xxxxxxx
73 | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx
74 | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2
75 | [\xE1-\xEC][\x80-\xBF]{2}
76 | \xED[\x80-\x9F][\x80-\xBF]
77 | [\xEE-\xEF][\x80-\xBF]{2}
78 | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3
79 | [\xF1-\xF3][\x80-\xBF]{3}
80 | \xF4[\x80-\x8F][\x80-\xBF]{2}
83 $chars = array( '' ); // Start with 1 element instead of 0 since the first thing we do is pop
85 // We had some string left over from the last round, but we counted it in that last round.
88 // Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
89 $pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
91 $chars = array_merge( $chars, $pieces );
92 } while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
94 return join( '', array_slice( $chars, $start, $length ) );
97 if ( ! function_exists( 'mb_strlen' ) ) :
98 function mb_strlen( $str, $encoding = null ) {
99 return _mb_strlen( $str, $encoding );
104 * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.
105 * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
106 * The behavior of this function for invalid inputs is undefined.
108 function _mb_strlen( $str, $encoding = null ) {
109 if ( null === $encoding ) {
110 $encoding = get_option( 'blog_charset' );
113 // The solution below works only for UTF-8,
114 // so in case of a different charset just use built-in strlen()
115 if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
116 return strlen( $str );
119 if ( _wp_can_use_pcre_u() ) {
120 // Use the regex unicode support to separate the UTF-8 characters into an array
121 preg_match_all( '/./us', $str, $match );
122 return count( $match[0] );
126 [\x00-\x7F] # single-byte sequences 0xxxxxxx
127 | [\xC2-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx
128 | \xE0[\xA0-\xBF][\x80-\xBF] # triple-byte sequences 1110xxxx 10xxxxxx * 2
129 | [\xE1-\xEC][\x80-\xBF]{2}
130 | \xED[\x80-\x9F][\x80-\xBF]
131 | [\xEE-\xEF][\x80-\xBF]{2}
132 | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences 11110xxx 10xxxxxx * 3
133 | [\xF1-\xF3][\x80-\xBF]{3}
134 | \xF4[\x80-\x8F][\x80-\xBF]{2}
137 $count = 1; // Start at 1 instead of 0 since the first thing we do is decrement
139 // We had some string left over from the last round, but we counted it in that last round.
142 // Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
143 $pieces = preg_split( $regex, $str, 1000 );
146 $count += count( $pieces );
147 } while ( $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
149 // Fencepost: preg_split() always returns one extra item in the array
153 if ( !function_exists('hash_hmac') ):
154 function hash_hmac($algo, $data, $key, $raw_output = false) {
155 return _hash_hmac($algo, $data, $key, $raw_output);
159 function _hash_hmac($algo, $data, $key, $raw_output = false) {
160 $packs = array('md5' => 'H32', 'sha1' => 'H40');
162 if ( !isset($packs[$algo]) )
165 $pack = $packs[$algo];
167 if (strlen($key) > 64)
168 $key = pack($pack, $algo($key));
170 $key = str_pad($key, 64, chr(0));
172 $ipad = (substr($key, 0, 64) ^ str_repeat(chr(0x36), 64));
173 $opad = (substr($key, 0, 64) ^ str_repeat(chr(0x5C), 64));
175 $hmac = $algo($opad . pack($pack, $algo($ipad . $data)));
178 return pack( $pack, $hmac );
182 if ( !function_exists('json_encode') ) {
183 function json_encode( $string ) {
186 if ( ! ( $wp_json instanceof Services_JSON ) ) {
187 require_once( ABSPATH . WPINC . '/class-json.php' );
188 $wp_json = new Services_JSON();
191 return $wp_json->encodeUnsafe( $string );
195 if ( !function_exists('json_decode') ) {
196 function json_decode( $string, $assoc_array = false ) {
199 if ( ! ($wp_json instanceof Services_JSON ) ) {
200 require_once( ABSPATH . WPINC . '/class-json.php' );
201 $wp_json = new Services_JSON();
204 $res = $wp_json->decode( $string );
206 $res = _json_decode_object_helper( $res );
209 function _json_decode_object_helper($data) {
210 if ( is_object($data) )
211 $data = get_object_vars($data);
212 return is_array($data) ? array_map(__FUNCTION__, $data) : $data;
216 if ( ! function_exists( 'hash_equals' ) ) :
218 * Compare two strings in constant time.
220 * This function was added in PHP 5.6.
221 * It can leak the length of a string.
225 * @param string $a Expected string.
226 * @param string $b Actual string.
227 * @return bool Whether strings are equal.
229 function hash_equals( $a, $b ) {
230 $a_length = strlen( $a );
231 if ( $a_length !== strlen( $b ) ) {
236 // Do not attempt to "optimize" this.
237 for ( $i = 0; $i < $a_length; $i++ ) {
238 $result |= ord( $a[ $i ] ) ^ ord( $b[ $i ] );
241 return $result === 0;
245 // JSON_PRETTY_PRINT was introduced in PHP 5.4
246 // Defined here to prevent a notice when using it with wp_json_encode()
247 if ( ! defined( 'JSON_PRETTY_PRINT' ) ) {
248 define( 'JSON_PRETTY_PRINT', 128 );